An apparatus according to the above for recording and more specifically a matrix printer is previously known from DE "Offenlegungschrift" 2 318 947. In the apparatus a spring is used to preload the head in a direction towards the record carrier. In order to manage printing on different types of documents the apparatus is provided with a pair of distance measuring means. When printing on thick document first distance measuring means in the shape of a wheel is effective, the wheel running along the document under a spring force. When the document is thinner, the first distance means becomes non-effective and the second distance means are then activated which also are in the shape of a wheel. This wheel runs along a guide rail located at a essentially constant distance from the print bed of the document. The head has a given constant distance to the print bed independent of the thickness of the document up to the thickness when the first distance measuring means takes over the distance adjustment of the head. For thin documents it may be observed that the distance of the head to the record carrier varies in accordance with the thickness of the document and that no contact is present between the head and the document.
The prior art apparatus according to the above has some disadvantages. When printing for example in a bank-book, the thickness of the document may vary substantially. In certain cases the printing may take place under conditions applicable for thin documents while printing in other cases takes place under conditions applicable for thick documents. For bank-books, it is desired that all of the printing occurs while maintaining a certain pressure against the document and accordingly this is not fulfilled in the prior art apparatus in the case when printing such sections of the book that comprise thin documents. Furthermore, the apparatus during the printing of the document may pass between a condition for printing of thin documents and a condition for printing of thick documents. Such possible passages may give rise to disturbances in the printing at the passage itself and differences in the printing in the finished document between sections printed under conditions for thin documents and sections printed under conditions for thick documents.